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(No Model.) 2 Sheets-Sheet 1.

. G.- SOHMID.

' SLIDE VALVE .No. 337,441. I Patented Mar. 9, 1886.

Mr E E2 6 1W6? 2g i Wiwssm: e Mafia w e I flaw/M 1 2 Shets-Sheet 2. U. SCHMIDQ I $LIDE VALVE. No. 337,441. Patented Mar. 9. 1886.

(No Model.)

N. PETERS PhnPo-Lilhognpllur. Washingtnn. D. C.

IIITED STATES PATENT Fries.

CHARLES SGHMID, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO GEORGE FARNSVVORTH, OF SAME PLACE.

8 LI DE-VALVE.

$PECIFICATION forming part of Letters Patent N 0. 337,441, dated March 9. 1886- Application filed July '7. 1885. Serial No. 170,847. (No model.)

To (rZZ whom it may concern:

. Be it known that 1, CHARLES SoHMIp, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Slide-Valve Mechanism for Steam-Engines, of which I do declare the following to be a full, clear, and exact description, reference being had to the accompanying 1o drawings, forming part of this specification.

My present invention has relation to the improvement of that class of slide-valve mechanism wherein means are employed to lessen the back-pressure or resistance in the cylinder upon the exhaust side of the piston, and in particular does it relate to the improvement of that form of slide-valve mechanism illustrated in the application of Dennis OB. vLadd, filed in the Patent Office on the 30th day of March, 1885. The invention of said Ladd embraced, primarily, a slide-valve having escape-ports therein provided with a suitable supplemental valve for opening and closing such escape-ports in such manner that there would be a free exhaust from the main cylinder during the time that the steam therein was acting both directly and expansively.

The supplemental valve in said application was controlled in its movements by auxiliary o pistons operated by steam and inclosed within the body of the main slide-valve.

In my improved form of valve mechanism hereinafter described I employ a main slidevalve having ports therein, through which the steam may escape from the exhaust side of the cylinder, and a supplemental valve, as in the Ladd construction; but instead of operating the supplemental valve by means of steam-actuated pistons, I provide the supple- 0 mental valve with mechanism adapted to cooperate with some relatively-fixed part of the engine structure (preferably the steam-chest) in such manner that as the slide-valve moves back and forth the supplemental valve will be shifted to open and close the escape-ports therein at the proper times.

My invention therefore consists, primarily, in the combination, with the main slide-valve having escape-ports, and having a supple- 5: mental valve to open and close said escapeports, of suitable mechanism leading from said supplemental valve to some relatively-fixed part of the structure, so that as the main valve is operated the supplemental valve will be automatically shifted to open and close the 5 5 escape-ports of the main. slide-valve.

My invention also consists in various details of construction hereinafter described, illustrated in the accompanying drawings, and particularly defined in the claims at the end of the specification.

Figure 1 is a view in vertical longitudinal section of a cylinder and steam-chest having a slide-valve of my improved construction applied thereto. Fig. 2 is a plan view of the slide-valve in position within the steam-chest. Fig. 3 is a plan view of the slide-valve with its cover removed to expose the subj acent parts. Fig. 4 is a plan view of the slide-valve with the supplemental valve and operating mech- 7o anism removed therefrom. Fig. 5 is a detail plan view of the supplemental valve. Figs.

6 and 7 are plan views of the connecting-bar and the slide-valve, the latter being shown in difierent positions in the two figures and the cover of the slide-valve being removed for better illustration of the subj acent parts. Fig.

8 is a view in central vertical section through the slide-valve, the supplemental valve, and its operating mechanism. Fig. 9 is a detail view in side elevation of the crank-pin for operating the supplemental valve. Fig. 10 is a plan view of the crank-plate at the outer end of the crank-pin.

A designates the main cylinder, provided 8 with the usual steamways, a and a, and exhaust-port a and B denotes the steam-chest, within which and upon its appropriate seat is placed the main slide-valve, that is operated by the valve-rod G in the usual manner. go This main slide-valve consists of the bottom plate, D, the sides D, which may be formed integral with the bottom plate, if desired, and the cover D", that is removably held in place by means of the screws d.

At a central point in the bottom plate, D, is formed the seat d, wherein journals the lower end of the crank-pin E, which extends throughv the supplemental valve F and through the top plate, D", of the main slide-valve. r0)

In the bottom plate, D, are formed the long escape-ports D and D, which admit steam from the steamways C6 and a of the main cylinder into the chamber of the main slide-valve, from which chamber the steam will escape through the ports D, that are in constant communication with the exhaust-port a" of the main cylinder.

Upon the bottom plate, D, and held within suitable guide-flanges, D, bolted to said plate, the supplemental valve F is held in a manner free to slide, for the purpose of alternately opening and closing the escape-ports D and D", and upon the under side of the top plate, D is fixed the bowed plate-spring G, which bears upon the face of this supplemental valve, and serves to securely hold the same against its seat.

In the supplemental valve F is formed the seat f, preferably of substantially the configuration shown-that is to say, having the circular sides and squared bottom, forming the stops or shoulders f and f"and within this seat or opening fits the crank-arm E, formed near the lower end of the crank-pin E.

Upon the squared portion 0 of the upper end of the crank-pin E, and resting upon the top plate, D", fits what I designate the crank plate or arm H, which is held in place upon the pin by means of the threaded nut h, and at the outer end of this crank-plate is placed a suitable pin, it, which extends through the long slot t of the fixed connection or connecting-bar I, that serves to determine the relation of the supplemental valve with respect to the slide-valve. The ends of the connectingbar I are preferably screw-threaded, as shown, and are adjustably held by means of the setnuts 1 and l" within the angle-bars K, bolted to the sides of the steam-chest.

From the foregoing description the operation of my improved slide-valve mechanism will be seen to be as follows: Assuming the parts to be in the relative positions shown by Fig. 1 of the drawings, at this instant live steam is being admitted from .the steam-chest B through the steamway a into the main cylinder behind the piston, and is being exhausted through the steamway a, escape-port I), the chamber of the main slide-valve, ports D and exhaust-port a into the open air. Steam thus continues to exhaust from the main cylinder until the main piston has completed its stroke, and not only while the live steam is being admitted through the steaniway a and is working directly, but also after the slide valve has cut off the steam from this steamway and the live steam in the main cylinder is working expansively.

The main slide-valve, in assuming the position shown by Fig. 1, has caused the supplemental valve F to close the escape-port D", for the reason that as the slide-valve moved forward the supplemental valve was prevented from making the complete movement of the main valve by means of the bar I, the pin h, the crank-plate H, the crank-pin E, and the crank-arm E within the seat of said supplemental valve, as follows: The pin it being held by the connecting-bar I, the main slide-valve as it moved beneath this bar carried with it the supplemental valve F until the crank-arm E came in contact with the stop or shoulder f of the supplemental valve, forcing the sup plemental valve to coverthe escapeport D as the main slide-valve continued its movement.

My purpose in forming the opening or seat for the supplemental valve with the curved sides and with the stops or shouldersf and f is to insure the same certain action of the supplemental valve in opening and closing the escape-ports D and D, irrespective of the length of stroke that maybe given to the main slide-valve, forit will be seen that even a very short stroke of the slide-valve will be sufficient to cause the crank-arm E to strike the stopsf andf while if the stroke be longer the crankarm will simply move along the curved side or openingf, and will not move the supplemental valve more than is required.

hen the main slide-valve is in position with respect to the steam chest and cylinder shown in Fig.1 of the drawings, the relative position of the main and the supplemental valves is that shown in Fig. 7 of the drawings. If, now, the direction of movement of the main slide-valve be reversed, in order to admit steam through the st-eamway ct, it will be noticed that during the initial reverse or backward movement ofthe main valve the supple mental valve F moves with it, and the escapeport D remains open and the escape-port D remains closed until the main valve has moved backward so far that the crank-arm ll contacts with the stop or shoulder of the supplemental valye, as seen in Fig. 3, and forces the supplemental valve to cover the escape-port D and uncover the escape-port D of the main valve. At this time the main and supplemental valves will be in about the relative positions shown in Fig. 6, and the main valve will have uncovered the stean'iway a partially, so that live steam can pass through this steamway to reverse the movement of the main piston. \Vhile steam is being thus admitted through the steamway a it will be exhausting through the steamway a, escapeport D, the chamber of the main valve, the escape-port D and exhaust-port a of the main cylinder,

and will continue so to exhaust during the entire backward stroke of the piston. It will thus be seen that the shifting of the supple- It will be readily understood that the de- [valve for opening-and closing said escape- 6 tails of construction above set out may be varied within wide limits without departing from the spirit of my invention. Thus, for example, various forms of mechanism for causing the shifting movement of the supplemental valve may be employed instead of the crank mechanism shown, and in some instances the connecting-bar I need not be rigidly attached to the steam chest, but may be fixed to the crank-plate H, and extended in suchrelation to the ends of the steam-chest that the bar will strike the walls of the chest as the slide-valve moves, and will thus cause the supplemental valve to shift. So, also, instead of the opening f being formed in the supplemental valve, this valve may be simply provided with stops at the points f and f against which the crankarm E shall strike.

If desired, the main slide-valve may be provided with an exhaust-cavity after the manner of'ordinary slide-valves, so that a portion of the exhaust at the end of the stroke, if the slide-valve is Working with full stroke, may occur through this exhaust-cavity and the exhaust-port a", in the usual manner. It is believed, however, that in practice the construction shown will be found satisfactory, as the exhaust in the manner above described will be found sufficient when the slide -valve is working in the usual manner, and if a very long stroke be made the escape-ports D? will serve to allow the escape of steam directly from the steamways into the exhaust-cavity of the main cylinder.

Instead of providing the crank-pin E with the arm E, it will be readily seen that an eccentric may be used instead of such arm, a suitable seat for such eccentric being formed upon the supplemental valve.

These and other changes involving the exercise of mechanical skill will readily suggest themselves to the skilled workman, and need not be more specifically set out.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In slide-valve mechanism, the combina tion, with the main slide-valve, having escape ports therein, and a supplemental valve for opening and closing said escape-ports, of suitable mechanism extending between said supplemental valve and some relatively-fixed part of the structure, and adapted to shift the said supplemental valve as .the main slidevalve is operated, substantially as described.

2. In slide-valve mechanism, the combination, with the main slide-valve having suitable escape-ports therein, and a supplemental ports, of mechanism for shifting said supplemental valve comprising a crank-arm,a crankpin, and a crank plate or rod suitably connected with the supplemental valve,and adapted to be operated from some relatively-fixed point of the structure, substantially as described.

'3. In slide-valve mechanism, the combination, with the main slide-valve having suitable escape-ports therein, and a supplemental valve for opening and closing said escapeports, of a crank-arm, a crank-pin, a crank plate or rod, and a bar extending from the steam-chest and connected with the crankplate in a manner permitting said crank-plate to shift, substantially as described.

4. In slide-valve mechanism, the combination, with the mainoslide-valve having escape ports therein, of a supplemental valve having suitable stops thereon, the crank E, adapted to engage with said stops during a portion of the travel of the valve, and a shaft for said crank provided with suitable means whereby its movement may be controlled by the steam-chest, substantially as described.

5. In slide-valve mechanism, the combination,with the main slide-valve having escapeports therein, of the supplemental valve F, having the seat f therein, the crank arm E, the crank-pin E, the crank-plate H, and the bar I, substantially as described.

6. In slide-valve mechanism, the combination, with the main slide-valve having escapeports therein, and the supplemental valve adapted to open and close said escape-ports, of a crank-shaft suitably connected to the supplemental valve, and an adjustable connectingbar between said crank shaft and the steam-chest, substantially as described.

7. In slide-valve mechanism, the combination, with the hollowmain slide-valve having escape-ports therein, and a supplemental valve within said slide-valve. of the spring for holding said supplemental valve to its seat, substantially as described.

8. In slide-valve mechanism, the combination, with the main slide-valve having escapeports therein, of the supplemental valve for opening and closing said escape-ports, having a suitable seat provided with stops or shoulders and with curved sides, a crank-arm, a crank-pin, a crank plate or rod, and a slotted connectingbar extending to the steam-chest, substantially as described.

. CHARLES SOHMID.

Witnesses:

(3130. P. FISHER, J r., J AMES H. PEIRoE. 

